Lub resistivity cuab yeej raws li hlau

Electrically conductive hlau hu ua lub sij hawm mus dhau los ntawm nws tus kheej them tam sim no. Nyob rau hauv lem, tus kuj yog hu ua ib tug ntawm cov yam ntxwv ntawm cov khoom. Qhov loj qhov hluav taws xob kuj ntawm ib tug muab voltage, tus me tus tam sim no lub dag lub zog. Nws characterizes cov tshuaj tiv thaiv kev quab yuam qhia raws tus neeg xyuas pib muaj lub suab ntawm them electrons. Txij li thaum hluav taws xob kis tau tus mob tej khoom vaj tse - yog reciprocal ntawm kuj, qhia raws li txhais li cas cov qauv nws yuav tsum yog tus piv 1 / R.

Resistivity yeej ib txwm nyob rau qhov zoo ntawm cov khoom uas yog siv nyob rau hauv qhov siv thiab ua kiag li lawm. Nws yog ntsuas, pib los ntawm lub tsis xyuas pib muaj ib tug ntev ntawm 1 'meter', raws li zoo raws li tus ntoo khaub lig seem cheeb tsam ntawm 1 square millimeter. Piv txwv li, cov kev kuj cuab yeej tooj liab yog yeej ib txwm sib npaug zos rau 0,0175 ohm rau txhuas - 0,029 hlau - 0,135, constantan - 0,48, nichrome - 1-1.1. Resistivity ua sib npaug zos rau cov xov tooj 2 * 10-7 Ohm • m

Countering tam sim no yog ncaj qha proportional rau qhov ntev ntawm ib tug neeg xyuas pib los ntawm kev uas nws txav. Qhov ntau dua qhov ntev ntawm lub ntaus ntawv, ntau dua qhov lub kuj. Internalize no kev sib raug zoo yuav yuav yooj yim dua yog tias koj xav txog tej yam ob xav txog tej yam khub ntawm interconnected hlab ntsha. Ib tug khub ntawm pab kiag li lawm txuas raj cia tshua nyias, thiab rau lwm yam - lub thickness. Thaum uas muaj cov dej rau ob tug officers ntawm kua tso cai nyob rau hauv lub sib txuas lus hlab ntsha nyob rau hauv lub tuab raj tau sai npaum li cas, vim hais tias nws yuav muaj tsawg kuj mus rau cov dej los ntawm ntws. Rau no analogy rau lub fais tam sim no, nws yog yooj yim los mus kis tau raws ib tug tuab neeg xyuas pib dua zoo.

Resistivity li cov SI unit, yog ntsuas los ntawm ohm • m. Conductivity nyob rau hauv lub phem free sib ntaus ntawm them hais, uas yog tsiag ntawv los ntawm cov qauv ntawm cov khoom. Co tsis muaj impurities, nyob rau hauv uas lub feem ntau yog siv lead ua ntxaij ntoo, yog tus nqi qis tshaj qhov tseem ceeb ntawm kev tiv. Nyob rau lwm cov tes, impurities distort cov lattice tshaj rau kom nws cov kev ua tau zoo. Lub resistivity ntawm hlau nyob rau hauv ib tug nqaim ntau yam ntawm muaj nuj nqis rau tej kev kub: los ntawm cov nyiaj thiab 0,016 mus rau 10 Hli • m (hlau hlau thiab chromium thiab txhuas).

Nyob rau hauv cov yam ntxwv ntawm cov lus tsa suab ntawm them electrons nyob rau hauv tus neeg xyuas pib muaj feem xyuam rau qhov kub thiab txias vim hais tias nws yuav tsub thaum tsub kom lub amplitude ntawm lub yoj oscillations uas twb muaj lawm ions thiab atoms. Raws li ib tug tshwm sim, lub electrons seem tsawg free chaw rau ib tug ib txwm khiav nyob rau hauv lub siv lead ua ntxaij ntoo. Qhov no txhais tau tias lub chaw khuam siab orderly zog nce. Lub resistivity ntawm tej conductors raws li ib txwm nce linearly nrog ua kub. Rau semiconductors, on qhov tsis tooj, tsiag ntawv los ntawm Txo tau cov nrog nce degrees, vim vim hais tias ntawm no muaj ntau yam nqi tso, creating ib tug hluav taws xob tam sim no ncaj qha.

Lub cua txias txheej txheem ib co paub hlau conductors mus rau lub yam kub resistivity coj lawv mus rau lub hopping lub xeev thiab ntog rau zero. Xws li ib tug tshwm sim sab nyob rau hauv 1911 thiab twb hu ua superconductivity.